Operating point for 6GK5

AKSA · 2nd October 2008, 09:56 AM

Looking at this tube, it's mu is 78, rp is 5400R. It would be a great candidate for a preamp using a trafo, say with 12:1 step down, giving overall gain around 6, 15.5dB. This should give a Zout around 40R, which would give it terrific drive. The only downside would be overload margin, probably not much better than 3Vpp.

Has anyone used this tube, could I ask your experience of the best operating voltages and currents for nicest sound?

Cheers,

Hugh

AKSA · 3rd October 2008, 11:00 AM

bump??

jazzbo · 3rd October 2008, 01:46 PM

Try to get in touch with Eric Kingsbury aka Poinz of AudioTropic. He uses the 6GK5 in his amp designs in a diff pair/driver. I have tried it driving an IT and was less than impressed but I didn't play around with operating points.

AKSA · 4th October 2008, 08:08 AM

Thanks Jazzbo,

Will speak to Eric.

Any others want to offer comment?

Tweeker · 4th October 2008, 11:27 AM

The 6GK5 is a frame grid, gain controlled triode designed for use as a VHF RF amplifier.

Bas Horneman · 4th October 2008, 12:56 PM

Gary Pimm uses them in his phono stage. 2,5mA or current running through it.

http://www.pacifier.com/~gpimm/phono.htm

kellymon · 6th October 2008, 03:21 PM

Hugh,
I just put together a little SET amp using the 6GK5 to drive a 1626.
The 6GK5 is battery biased (Nimh) at about 1.3vg/6ma and the 1626 @ 23v/23ma.
I needed the gain up front because my signal source is only 200mv (old computer CD drive line out)
So far I'm liking it a lot.
robert

2nd October 2008, 09:56 AM	#1
AKSA diyAudio Member Join Date: Sep 2001 Location: Melbourne, Australia	Operating point for 6GK5 Looking at this tube, it's mu is 78, rp is 5400R. It would be a great candidate for a preamp using a trafo, say with 12:1 step down, giving overall gain around 6, 15.5dB. This should give a Zout around 40R, which would give it terrific drive. The only downside would be overload margin, probably not much better than 3Vpp. Has anyone used this tube, could I ask your experience of the best operating voltages and currents for nicest sound? Cheers, Hugh __________________ Aspen Amplifiers P/L (Australia) www.aksaonline.com

3rd October 2008, 11:00 AM	#2
AKSA diyAudio Member Join Date: Sep 2001 Location: Melbourne, Australia	bump?? __________________ Aspen Amplifiers P/L (Australia) www.aksaonline.com

4th October 2008, 08:08 AM	#4
AKSA diyAudio Member Join Date: Sep 2001 Location: Melbourne, Australia	Thanks Jazzbo, Will speak to Eric. Any others want to offer comment? __________________ Aspen Amplifiers P/L (Australia) www.aksaonline.com

4th October 2008, 11:27 AM	#5
Tweeker diyAudio Member Join Date: Dec 2004 Location: Cincinnati, Ohio	The 6GK5 is a frame grid, gain controlled triode designed for use as a VHF RF amplifier. __________________ Be sure your foil hat has a good low impedance ground.

4th October 2008, 12:56 PM	#6
Bas Horneman diyAudio Moderator Emeritus Join Date: Apr 2002 Location: The Netherlands Blog Entries: 18	Gary Pimm uses them in his phono stage. 2,5mA or current running through it. http://www.pacifier.com/~gpimm/phono.htm __________________ Boatanchor amps forum My "adventures" in audio


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3rd October 2008, 01:46 PM	#3
jazzbo diyAudio Member Join Date: May 2007	Try to get in touch with Eric Kingsbury aka Poinz of AudioTropic. He uses the 6GK5 in his amp designs in a diff pair/driver. I have tried it driving an IT and was less than impressed but I didn't play around with operating points.

6th October 2008, 03:21 PM	#7
kellymon diyAudio Member Join Date: Jun 2008	Hugh, I just put together a little SET amp using the 6GK5 to drive a 1626. The 6GK5 is battery biased (Nimh) at about 1.3vg/6ma and the 1626 @ 23v/23ma. I needed the gain up front because my signal source is only 200mv (old computer CD drive line out) So far I'm liking it a lot. robert

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